Not building a 409 .. Im not to much of a speedster haha.. need something to cruise low and slow.. as they say.. haha
I dig the Elky. The truck is cool, but the Elky with Cragars is Badass. And 301s are not a small time engine. My Avatar has a dual quad 301 with a 39 trans and it pulls the front wheels off the ground when you dump the clutch.
Trucks can be hard to move. I admit, I am biased towards the El Camino's, but comparing the two, non emotionally, I'd go for the El Camino hands down, provided the rust is minor and fixable. look under the bed floor, and at the floor pans.
I believe the El Camino is worth a little more. They reproduce about any kind of panel imagineable for those, short of a roof skin or something. It's probably a good swap, it's just a matter of whether you like the '60 enough to want it.